arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1901.07424astro-ph.SR
收藏

太阳S-爆发的性质和磁源

Properties and magnetic origins of solar S-bursts

Brendan P. Clarke, Diana E. Morosan, Peter T. Gallagher, Vladimir V. Dorovskyy, Alexander A. Konovalenko, Eoin P. Carley

摘要:

上下文太阳活动经常伴随着太阳射电辐射,包括许多类型的太阳射电爆发。在低频(<100兆赫),持续时间短至毫秒的射电爆发,如太阳S-爆发,已经被发现。迄今为止,它们的起源和许多特征仍不清楚。目的。我们报告的观察,从乌克兰的T形射电望远镜,(UTR-2),和低频阵列(LOFAR),这给了我们新的见解,他们的性质。方法. 2013年7月9日,在太阳活动较低的时期,观测到超过3000个频率为17.4-83.1 MHz的S-爆发。通过分析S-爆发的光谱特性和估计日冕磁场强度,对S-爆发产生的主要模型进行了测试。结果发现S-爆发具有0.5-0.9 s的短持续时间。使用多种仪器测量漂移率对频率的依赖性,其由指数为1.57的幂律表示。我们首次在宽频带上证明了瞬时带宽与频率之间的线性关系。UTR-2的通量校准和高灵敏度使得能够测量它们的通量,得到11+3 SFU。S爆发的源粒子速度约为0.07 c。S-爆发源高度的范围从1.3 R_Sun到2 R_Sun。此外,一个当代的理论模型的S-爆发的产生进行遥感的日冕磁场在这些高度产生的值为0.9-5.8 G。在误差范围内,这些值与日冕中磁场强度和高度之间的各种关系所预测的值相当。

英文摘要:

Context. Solar activity is often accompanied by solar radio emission, consisting of numerous types of solar radio bursts. At low frequencies (<100 MHz) radio bursts with short durations of milliseconds, such as solar S-bursts, have been identified. To date, their origin and many of their characteristics remain unclear. Aims. We report observations from the Ukrainian T-shaped Radio telescope, (UTR-2), and the LOw Frequency ARray (LOFAR) which give us new insight into their nature. Methods. Over 3000 S-bursts were observed on 9 July 2013 at frequencies of 17.4-83.1 MHz during a period of low solar activity. Leading models of S-burst generation were tested by analysing the spectral properties of S-bursts and estimating coronal magnetic field strengths. Results. S-bursts were found to have short durations of 0.5-0.9 s. Multiple instruments were used to measure the dependence of drift rate on frequency which is represented by a power law with an index of 1.57. For the first time, we show a linear relation between instantaneous bandwidth and frequency over a wide frequency band. The flux calibration and high sensitivity of UTR-2 enabled measurements of their fluxes, which yielded 11+3 SFU. The source particle velocities of S-bursts were found to be ~0.07 c. S-burst source heights were found to range from 1.3 R_Sun to 2 R_Sun. Furthermore, a contemporary theoretical model of S-burst generation was used to conduct remote sensing of the coronal magnetic field at these heights which yielded values of 0.9-5.8 G. Within error, these values are comparable to those predicted by various relations between magnetic field strength and height in the corona.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑